There may, perhaps, be various situations in which it is desirable to be able to automatically reposition a rotary platform to a selected position which it occupied initially.
While the present invention appears to be generally applicable to rotary platforms, and the method of automatically repositioning same, it has found its initial application to a particular type machine, namely, a vertical augur drill carried by a derrick that is in turn supported on a rotary platform, the rotary platform being transportable by a wheeled carrier.
In operating a vertical augur drill for drilling water wells and the like it is periodically necessary to lift the augur from the hole in order to shake out the cuttings. Before shaking out the cuttings, however, the augur must be moved considerably to one side of the hole, in order to avoid having the cuttings fall back down into the hole. When the augur is carried by a derrick that is in turn supported from a rotary platform, it is, therefore, the practice to rotate the rotary platform a number of degrees in one direction or the other before shaking the cuttings from the augur. When the cuttings are shaken from the augur the rotary platform is then returned to its initial position, and the augur is again lowered into the hole for further drilling of the hole.
In such operation of a vertical augur drill it has heretofore been the practice for the operator of the machine to manually control the movements of the rotary platform, including both the rotation of the platform away from the hole before the augur is shaken, and the rotation of the platform back to the hole after the shaking action has been completed.